Window Condensation: Understanding What It Means

November 7, 2018

It’s almost that time of year where energy efficient windows can affect your heating expenses by holding more temperate air in your room while defending against the elements outside. However, you may start to find condensation gathering on your windows and doors during colder months.

If you find condensation on your window, don’t panic! It isn’t time to start looking for something wrong with your window. As a matter of fact, condensation on the inside of your windows—known as roomside condensation—isn’t a sign of a defective window at all. Instead, it means your windows are working well.

So, what is creating the condensation on your windows? And, more importantly, what signs of condensation should raise alarms about your window’s health? Here are the facts about window condensation:

Do my new windows or doors create condensation?
Some homeowners associate the signs of condensation in the months after installing new windows with unnoticed problems during the installation process. Condensation on windows and doors is not created by the window or door product. Actually, it comes as a result of high humidity levels in your house.

As it turns out, the signs of condensation more often than not is an outcome of the improved energy efficiency of your new windows. Air with increased humidity keeps water vapor until it comes into contact with a surface temperature less than or equal to the dew point—the temperature at which air becomes saturated and produces dew. Due to the fact that glass surfaces are most likely the coldest part of the house, condensation can be seen on windows more frequently, in the indication of water droplets or frost on the roomside of your window. As the air inside gets drier, or as the glass surface becomes warmer, condensation begins to dissipate.

Numerous factors go into whether you might notice condensation on your windows. You might even discover that a window in one part of your room has roomside condensation while another in the same room doesn’t. Air circulation, varying room temperatures, air register location, and the type and size of the window can all influence the likelihood of roomside condensation. Other influnences such as glass type, window coverings and screens and proximity to a water source can all have an impact on what levels of humidity can be noticed around a window.

Why do I occasionally see condensation on opposite sides of the window?
Your previous windows could have been drafty or didn’t feature the advanced, energy efficient elements of modern windows. But, other home repairs, such as building a new roof or siding, might also establish a tighter seal against air infiltration in your room. As a result, your home may hold more humidity making condensation more likely to happen than before.

In the summer months, this same phenomenon can be noticed on the outside of your windows. Exterior condensation can gather due to high outdoor humidity, little or no wind, and a clear night sky. It grows in the same way as roomside condensation, when the temperature of the glass is cooled below the dew point of the outside air. Since the cooler air inside your house isn’t escaping due to increased energy efficiency, there’s a greater chance to see external condensation at times like these.

You can address exterior condensation by opening curtains at night to warm up exterior glass and promote air circulation by trimming any shrubbery that might be blocking windows. Programming the air conditioner a few degrees warmer can also make a difference.

For roomside condensation, there are a number of factors that can determine the humidity in your home. Here are a few common culprits that can cause roomside condensation:

The most common way roomside humidity increases is through everyday home activities. Running showers and baths, cooking and washing dishes, doing laundry, even the dog’s water bowl can all increase moisture to the air in your home–up to four gallons or more per day in some homes. Include today’s energy efficient, well-insulated homes and you can start to get an idea why that humidity can often find no way to escape.

Because of this better insulation, some windows can build a strip of condensation that shows up all the way around the roomside of the window. Usually, this happens when the center of the glass stays warmer than the glass closest to the edge. It isn’t an indication that the window is leaking air or not functioning correctly.

Can Roomside Condensation Damage My Windows?
One place where condensation on windows should become an immediate issue, however, is if condensation is seen between the two sealed panes of insulating glass in multi-pane windows. In this case, condensation is a sign of seal failure and the insulating glass will need to be replaced.

More often than not though, condensation on your windows doesn’t mean there is a concern with your windows. It serves as a sign to the possibility of other unseen, potentially costly problems to be found in your home.

High indoor humidity can eventually cause structural damage and even upset your health. Because these effects frequently go without notice in the wall cavities, attics and crawl spaces, the visible sign of condensation on glass is a good sign that humidity levels are too high. And while window condensation and musty odors might be seen as annoyances, they can grow into more severe concerns such as water stains on walls and ceilings if left unresolved.

In the same way, left unaddressed, condensation issues can lead to window problems over time. Make sure to take chronic roomside condensation seriously. Think of it as an early alarm to high humidity in your home, one that can easily be resolved before it gets serious. Understanding condensation is just the beginning to keeping your home cozy and maintaining your windows. If you have any questions about condensation and whether your windows and doors are doing their jobs as they should, give Pella Windows and Doors in Greensboro a call or visit the showroom.